Trade-offs between energy consumption and neuronal performance must shape the design evolution of nervous systems, but we lack empirical data showing how costs vary according to performance. Using intracellular recordings from intact retinas four flies, Drosophila melanogaster, D. virilis, Calliphora vicina, Sarcophaga carnaria, measured rates at which homologous R1-6 photoreceptors these species transmit information same stimuli estimated they consumed. In all species, both rate increase...

Activity-dependent morphological plasticity of neurons is central to understanding how the synaptic network CNS becomes reconfigured in response experience. In recent years, several studies have shown that activation leads induction long-term potentiation also drives growth new dendritic spines, raising possibility synapses are made. We examine this directly by correlating time-lapse two-photon microscopy newly formed spines on CA1 pyramidal organotypic hippocampal slices with electron...

The frontal eye field (FEF) of the primate neocortex occupies a pivotal position in matrix inter-areal projections. In addition to its role directing saccadic movements, it is source an attentional signal that modulates activity neurons extrastriate and parietal cortex. Here, we tested prediction FEF preferentially excites inhibitory target areas during modulation. Using anterograde tracer biotinylated dextran amine, found projections from terminate all cortical layers area 46, lateral...

The pattern of excitatory and inhibitory inputs to the neurons is largely unknown. We have set out quantify major layer 4 basket cells from primary visual cortex cat. synapses formed with soma, proximal distal dendrites, were examined at light electron microscopic levels in four cells, recorded vivo filled horseradish peroxidase. afferents been well characterised, both levels. sizes synaptic boutons thalamic relay spiny stellate 6 pyramidal are statistically different. Their distributions...

The primary visual cortex (V1) and V2 together form ∼24% of the total neocortex macaque monkey have each other as their major partners. target V1 projection to is layer 4, where it forms clusters boutons, which asymmetric (excitatory) synapses mainly with dendritic spines (75%). remainder shafts. found on were often more complex, perforated postsynaptic densities than those reciprocal from targeted layers 1, 2/3, 5 was formed axons different morphologies. One axon type, originating...

The action potential discharge response of single neurons to both visual stimulation and injections current were obtained during intracellular recordings in cat cortex order estimate the net excitatory arriving at soma stimulation. Of 45 recorded intracellularly, 19 pyramidal one basket cell labelled with horseradish peroxidase. all adapted constant current. For 40 neurons, a exponential provided good fit adapting (r2 = 0.73 +/- 0.03) for intensities. Superficial layer significantly faster...

Area V5 (middle temporal) in the superior temporal sulcus of macaque receives a direct projection from primary visual cortex (V1). By injecting anterograde tracers (biotinylated dextran and Phaseolus vulgaris lectin) into V1, we have examined synaptic boutons that they form electron microscope. Nearly 80% target cells were spiny (excitatory). The formed asymmetric (Gray's type 1) synapses with spines (54%), dendrites (33%), somata (13%). All somatic targets some (26%) dendritic shafts showed...

Differences in behaviour exist between the sexes of most animal species and are associated with many sex–specific specializations. The visual system male housefly is known to be specialized for pursuit that culminates mating. Males chase females using a high–acuity region fronto–dorsal retina (the 'love spot') drives neural circuitry. We show love spot photoreceptors combine better spatial resolution faster electrical response, thereby allowing them code higher velocities smaller targets...

Abstract The synaptic input of six spiny stellate neurons in sublamina 4A cat area 17 was assessed by electron microscopy. were physiologically characterized and filled with horseradish peroxidase vivo. After processing the reconstructed at light microscopic level using computer‐assisted methods analyzed quantitatively. extensive branching dendritic tree about 50 μm from soma meant that distal branches constituted five times length proximal dendrite. Proximal portions a single dendrite each...

The V2 projection to V3A was labeled by pressure microinjecting biotinylated dextran amine (BDA) and Phaseolus vulgaris lectin (PHA-L) into just posterior the lunate sulcus. Dense terminal labeling in clusters found layer 4, with a weaker 3. About 3.5–4.1% of synapses densest bouton 4 were made boutons. All asymmetric (Gray's type 1) synapses, spiny, excitatory neurons. most frequently encountered synaptic targets spines (76% 98% 2/3). remainder dendritic shafts, which less than half (44%)...

Abstract The major target of the V4 projection in V2 is layer 1, where it forms a tangential spread asymmetric (excitatory) synapses. This characteristic “feedback” projection. Some axons formed discrete clusters bouton terminaux between lengths myelinated axon, while others were unbranched and continuous distribution en passant boutons with no intercalated myelin. Minor projections found layers 2/3 6. Dendritic spines most frequently encountered targets (80% 1 2/3, 94% 6). remaining...

Single neurons were recorded in the striate visual cortex (area 17) of old-world monkey Macacus namestrinus. Eight pyramidal neurons, seven spiny stellate neu rons, two basket cells, a clutch cell, and chandelier cell filled intracellulary with HRP. Their receptive fields consistent previous single-unit studies. axonal arbors less elaborate than equivalent cat, but laminar specificity houtons was very much more precise cat. Nevertheless, basic cortical circuits cat appear to hevery similar.

Current models of embryological development focus on intracellular processes such as gene expression and protein networks, rather than the complex relationship between subcellular collective cellular organization these support. We have explored this behavior in context neocortical development, by modeling expansion a small number progenitor cells into laminated cortex with layer cell type specific projections. The developmental process is steered formal language analogous to genomic...

Abstract The extrastriate visual area of the macaque monkey called MT or V5, receives its input from multiple sources. We have previously examined synaptic connections made by V1 cells that project to (Anderson et al., 1998 ). Here, we provide a similar analysis projection V2 MT. major target in is layer 4, where it forms clusters asymmetric (excitatory) synapses. Unlike projection, also synapses layers 1 and 2 does not form 6. most frequently encountered targets boutons labeled were spines...

We studied the interaction of proteoglycan subunit with both types I and II collagen. All three molecular species were isolated from ox. Type collagen, prepared papain-digested bovine nasal cartilage, was characterized by gel electrophoresis, amino acid analysis CM-cellulose chromatography. By comparison type calf skin, native skin acid-soluble tropocollagen, we concluded that papain treatment left collagen molecules intact. Interactions carried out at 4 degrees C in 0.06 M-sodium acetate,...

The formation of collagen fibrils under physiological conditions ionic strength, pH and temperature was markedly affected by the presence small amounts bovine tendon glycoprotein. absorbance gels at 400 nm decreased, they took longer to form. Over range concentration tested, negative specific absorbance, -delta Asp., retardation, Rsp., both increased with glycoprotein ratio. When added during nucleation phase, still able exert its effect almost fully, so must act inhibit later stages fibril...

The thalamic input to area 17 in the cat can be divided into at least three parallel pathways, W, X, and Y. Although latter two are some of best studied synaptic connections brain, former remains poorly understood both structure function. By combining light electron microscopy, we have reconstructed 3-D single W axons described quantitatively synapses that they form. We also made a structural comparison from visual pathways. Thalamic were labeled vivo by injections biotinylated dextran amine...

The carboxyterminal processing protease of D1 protein (CtpA) is predicted to be an excellent target for a general broad-spectrum herbicide. gene spinach CtpA has been expressed in Escherichia coli. that was found mainly inclusion bodies purified and refolded on nickel-chelate column. Active recombinant recovered. Two assays activity were developed, medium-throughput HPLC assay using fluorescent substrate high-throughput based fluorescence polarization capable application 96-well plate...